1. Field
The present disclosure relates generally to systems and methods for winding and unwinding linear material and, in particular, to a motorized reel having a motor controller for controlling the same.
2. Description of the Related Art
Linear material, such as hoses, ropes, cables, and electrical cords, can be cumbersome and difficult to manage. Mechanical reels have been designed to help wind such linear material onto a spool member. As used herein, a spool member is an element on which a linear material can be wound and unwound, such as a cylindrical drum. Some conventional reels are manually operated, requiring the user to physically rotate the spool member to wind the linear material about the spool member. This can be tiresome and time-consuming for users, especially when the linear material is of a substantial length. Other reels are motor-controlled, and can automatically wind up the linear material. These automatic reels often have a gear assembly wherein multiple revolutions of the motor cause a single revolution of the spool member. For example, some conventional automatic reels have a 30:1 gear reduction, wherein 30 revolutions of the motor result in one revolution of the spool member.
However, when a user attempts to pull out the linear material from the automatic reel, the user must pull against the increased resistance caused by the gear reduction because the motor spins 30 times for every full revolution of the spool member. Not only does this place an extra physical burden on the user, but the linear material experiences additional strain as well. Some automatic reels include a clutch system, such as a neutral position clutch, that neutralizes (or de-clutches) the motor to enable the user to freely pull out the linear material. This often requires the user to be at the site of the reel to activate the clutch. In addition, clutch assemblies can be expensive and substantially increase the cost of automatic reels.
For these reasons, some motorized reels include a motor controller that provides a “powered-assist” (also known as “reverse-assist”) feature, in which the motor controller detects when a user pulls the linear material from the spool member, and responds by operating the motor to rotate the spool member in a direction that unwinds the linear material. Powered-assist thereby reduces the pulling burden that is otherwise placed on the user. In one known implementation, the motor controller detects when a tension in the linear material exceeds a predetermined threshold, and responds by signaling the motor to rotate the spool member in an unwind direction.
Conventional automatic reel motors also tend to rotate the spool member at a constant rate. As a result, when the end portion of the linear material is being wound upon the spool member, such rotation can cause the end of the linear material to swing uncontrollably or even hit forcefully against the reel unit. This erratic movement can result in property damage or serious injury to nearby persons who may be hit by the linear material. Oftentimes, the user must also push a button or activate a control to stop the spool member from rotating. To account for such problems, some automatic reels incorporate encoders that keep track of the amount of linear material left to be wound. By tracking the amount of unwound linear material, a reel's motor controller can reduce the wind-up speed of the spool member when winding in the terminal end portion of the linear material. This feature is known as “docking.”